Switch assembly



R. C. WOOFTER SWITCH ASSEMBLY Dec. 26, 1961 2 Sheets-Sheet .1

Filed Dec. 11, 1958 Q Q INVENTOR.

19 7' TOR/VA". Y

Dec. 26, 1961 R.'c. WOOFTER SWITCH ASSEMBLY 2 Sheets-Sheet .2

INVENTOR. fiezfdZ Jmfifez ATTO/PMEV Filed Dec. 11. 1958 United States Patent 'This invention relates generally to switch assemblies and is particularly adapted for use. with various combinations of energizing and holding circuits, The'invention will described in connection with the circuitry for energizing electromagnetically-operated clutch assemblies used on automotive and other types of vehicles to estab lishand hold a throttle in any desired openposition. Whilethe switch assembly set forth herein is particularly adapted for the type of application set forth herein, it will be appreciated that there are many other applications for such a switch too numerous to mention. A

One of the primary objects of the invention is to provide a switch assembly which has three operating positions: One in which no contacts are closed, a second in which two sets of contacts are closed and an intermediate position in which'only one set of contacts is closed.

A further object of the invention is to provide biasing means in the assembly which when the switch is in one of its operating positions urges the contacts thereof toward another position. More specifically, when the contacts of the switch are in the operating position in which all of the 'sets of the contacts are closed it is being urged toward a positionin which only part of the sets of contacts of the switch is .closed. 1

For a 'fuller understanding of the invention and the above and other objects thereof, reference may be made to the accompanying detailed description and drawings in which:

FIGURE 1 is a view in plan of the upper side of the switch assembly having superimposed thereon a schematic diagram representing circuitry of the type used to control and operate the throttle hold devices for trucks, automotive and other types of vehicles.

FIGURE 2 is a side elevational view taken substantially on the line 22 of FIGURE 1 with parts in section and broken away to illustrate many of the internal details of construction of the switch.

FIGURE 3 is a view looking down on the switch taken substantially on the line 3-3 of FIGURE 2 further illustrating internal details of construction of the switch assembly.

FIGURE 4 is a view taken substantially on the line 4-4 of FIGURE 1.

FIGURE 5 is a view taken substantially onthe line 55 of FIGURE 3 illustrating the manner in which the operating rod of the switch is secured to the movable contact carrier of the switch.

FIGURE 6 is a view looking upward-1y taken on the line 66 of FIGURE 2 and shows the intermediate position of the contact carrier of the switch in which only one set of the switch contacts is bridged.

Turning now to the. drawings, the switch assembly includes an outer 'box or housing 2 comprising an upper side 4, two sides 6 and 8 and ends 10 and 12. The box or housing 2 is closed by a lower cover plate 14 which is secured to the housing 2 by studs 16. The box 2 and cover 14 form an inner elongated chamber 18 in which is movable back and forth a contact carrier block 20. The block 20, which is made of some suitable insulating material, is provided with two longitudinally extending recesses 22 and 24 side by side which contain bridge contactors 26 and 28, respectively, both supported at opposite ends thereof by small helical coil springs 30.

. in the side 4 and flush with the inside surface 32 of upper side 4 are two sets of longitudinally spaced contacts 34,. 36 and 39,v 40, respectively. The sets'o'f contacts 34,36 are adapted to bev bridged by the bridge contact 26 and the sets of contacts 38, 40 are adapted to be bridged by the bridge contact 28. .The contacts 34,

" 36; 3s, 40 are provided with suitable shanks 42 which extend-through the upper side 4 and have. bifurcated ends 44 to anchor suitable terminals 46, 48, 50, 52,. respectively.

Asecond'recess 54 is provided in the lower part of the contact carrier block 20 in which is located a helical coil spring 56 and a 'pair of washers 58, 60, all of which are mounted on a rod 62 extending through the recess 54 ,to

the oppositeends 10 and12 of housing 2, The rod 62 is I pinched at the" points 64 and 66 so as to limit the movement of spring 56 between these two points. Theiwasher. 58 abuts an end wall 68 of the recess 54 of carrier 20 thereby urging the carrier to the left'as viewed in FIG- URE 2 'under, the influence of spring 56. Extending through the end wall 12 of housing 2-is an operating rod or bar 70 having an operating handle 72 threaded on one. end thereof. The bar 70 extends into a third recess 74 in carrier 20 and has a reduced portion 76 which is in alignment'with'a cut-out portion 78 of recess 74. A spring retainer 80 has one end snapped over a shoulder 82 of carrier 20 and extends-from adjacent one side of the carrier to the other through the space provided by the necked-down portion 76 so as to fasten the operating rod 70'to carrier 20. The spring retainer 80 which is 'U-shaped in configuration is provided with a leg and foot I 84 which is adapted to be engaged by a small spring biased plunger 86 to thereby depress the spring'retainer 80 and release the operating rod 70 from its connection to carrier 20.

l, 2 and-3, the cover plate 14 extendsbelow the end 12 of housing 2 and is" provided with a boss portion 88 having internal threads in which is threaded a bushing 90 forming a slide bearing for rod 70.

Referring now to FIGURE 1, a circuit has been superimposed on this view of the switch assembly and includes a battery 92 having one end grounded and the opposite end connected to a switch 94. A second switch 96 which is normally closed but opens in response to vehicle brake pedal 98 immediately precedes connection of one of the contacts of switch 96 to the terminal 46 of the switch as sembly. An electromagnet which is symbolically shown by the coil 100 has one end grounded and the opposite end connected by a conductor 102 to terminal 50. The electromagnet 100 is shown as controlling a switch 104 located between electromagnet 100 and terminal 52. Terminals 48 and 52 are connected together by a conductor 106. The electromagnet 100 may be used in devices which are adapted to maintain the throttle of a vehicle in any desired open position to clutch the throttle or a part of its linkage to any suitable support so that the throttle cannot be moved with respect to whatever position it may be in at the time of energization of electromagnet 100. The operation of the switch assembly is as follows:

Assuming that an operator of a vehicle has his throttle in a certain desired open position and he wishes to maintain the throttle in this position so that he can remove his foot from the throttle pedal, he would grasp the handle 72 and pull it to the right or outwardly as viewed in FIGURES 1 and 2 until an end 108 of carrier 20 abuts a shoulder 110. When the carrier 20 is moved to this extreme position to the right as viewed in FIGURES 2 and 3, the spring will be compressed between the point 66 and the end wall 68 of carrier 20. In this extreme position the bridge contactors 26, 28 will bridge their associated sets Patented Dec. 26, 1961 Tu'rningagainsfor a moment particularly to FIGURES 3 of contacts 34, 36" and-'38, 40. Assuming switch 94 and brakeswitch' 96 to'b'e closed; current may nowflow from" the battery 92 through switches 94 and 96, through terminal 46, across the bridge cont actor 2 6, through teruiinal 48'," conductor 106' to" terminal 52; through the bridge con'tactdr 281'0' terminal so na' throu h-conductor" 102 to'elec trorna'gnet" 100' thereby'ene'rgi'zing the eiectro When" electromagnet 100' is" energized it will magnet. close switch 104 so that current nia'yalso ncw-flow'frorr th'ebattery 92 through switch 94; 96, across terminals 46, 48 through bridge contactbr 26, through conductor 106'; through terminal 52;. conductor I12 and sw'itcli' lfld to electro'magnet 100 thereby maintainingit energized;

If" now the handle 72 is releas'ed'the carrier 20" will be movedto' the left as viewe'd in FIGURE 2' to the position shown by action of the spring56, In this positionbridgc contactor 28 will no longerbridge' its contacts 38, 40as' indicated in FIGURE S 2 and 6'; Contacts 3 4; 3'6,1h'o'W-' ever, will remain connected together" by their bridge" contactor' 26 so that electroma'gnet 100' may bemaintained energized by the circuit. last traced out. If the operator" should now depress the brake pedal 9 8 it would be widesit-able to have'the throttle remain in this open position. Accordingly, depressionofbrake pedal 98'will open switch 96' thereby breaking the circuit through the switch and deener'gizing'ele'ctromagnet 100. De'en'ergizatio'n of'ele'ctrom'agnet 100 will openfs witchlMsofthat'now the o'nly' way that the throttle hold circuit" be reenergiz'ed t] again pull the handle- 72 to th'e' right as viewed'iri' FIG- URE 2 to'reestablish energi'zation ofthe'ielectromagiiet" 100 in themanner previously described. The operator can render the throttle hold" device inactive" merely by' pushing the handle 72 until'the wall 680!" theco'ntact carrier 20 engagesa" shou'lde'r'114of h'ousingyZi Neither bridge'contact's26 nor z8 will'then engage the associated co'ntacts"34-and 36 or 3'8 and 40, respectively.

From the foregoing descriptionit will be appreciated that a unique switch assembly has been dacribed which has unusualoperating characteristics. In its first position,

none of the contacts of theswitch' are electrically'oo'm' nected together. In a second position all of the contacts are'conneeted tegther; and in a third position to which the movable contacts of the switch are urged when in the second position only part of the contacts are electrically connected together. The switch is particularly adapted for applications ofthe type used as an example here.

I claim: I

A switch assembly comprising an insulated housing having a longitudinal recess therein receiving a contact carrier block; a first pair of contacts in said housing and extending into said recess in generally longitudinal alignment with said recess and-a second pair of contactsin said housing in generally parallel alignment with and transsecond'contactbridgingmembers mounted'on said carrier blocktor engaging and bridging the contacts'of each of said contact pairs, said" carrier block beingniov-able to a first position so that neither of said bridging members bridge said'c'on'tac't's and normally positioned in a second position wherein one ofsaid bridging members bridges one of said contactpairs' and movable to a-third position wherein each of said bridging members bridge one of saidcontact' pair's, a' carrier control rod extending through oneend of said housing, and spring. means mounted on saidcarrier and locking said control rod to said carrier whereby said co'n'trol'rod may move said carrier to each of said positions, said springbe'ing movable to disengagesaid rodfrom said'c'a'r'rier. 

